The NFLPA along with the NFL extended the deadline for the players association to file a collusion grievance against the league's owners.

"The NFL and NFLPA have agreed to extend the deadline for the players' to file a collusion claim," the two sides said in a joint statement Tuesday. "This agreement does not prevent the NFLPA from filing a collusion claim at a future date. We are continuing to work toward a new CBA that will be good for players, owners and fans."

A new deadline has not been announced and NFLPA spokesman George Atallah wrote in an e-mail to The Associated Press that he was "legally obligated" from revealing the new deadline.

The NFLPA has been building a case since only one of 216 restricted free agents were signed to an offer sheet during the offseason, union sources told ESPN on Sunday.

NFLPA executive director DeMaurice Smith is reviewing the case that has been collected by his legal team and had been expected to approve a collusion filing with the Special Master by Wednesday's deadline.

The Wednesday deadline was dictated by the current collective bargaining agreement. The Dec. 8 deadline was established as within 90 days of the regular-season opener, which was Sept. 8.

While many details have not been revealed, union sources concede that previous reports of a collusion case center on the lack of activity with the 216 restricted free agents, whose number quadrupled in size because of the uncapped-year rules in 2010. The union has gathered what it believes is similar dialogue that a variety of teams expressed when communicating with agents who represented the players, a source said.

Saints running back Mike Bell was the only restricted free agent to sign an offer sheet. The Philadelphia Eagles acquired his services when New Orleans declined to match the offer.

While Bell's signing represented less than 1 percent of the restricted free agent class in 2010, the comparison to 2009 is debatable, inasmuch as only four of 55 restricted free agents, or 7 percent, were signed to offer sheets with none changing teams.

Jeff Pash, the NFL's vice president of legal counsel/labor and point man, has previously stated that the uncertain labor future in 2011 accounted for the lack of restricted free agent activity.

The union's collusion charges, if filed, include other elements of what it considers illicit activity, a source said.

Chris Mortensen is ESPN's senior NFL analyst. Information from The Associated Press was used in this report.